| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] because it is difficult | 8 |
|
| 2 | [adv] because it is difficult | 7 |
|
| 3 | because it is [adv] difficult | 16 |
|
| 4 | because it is [adv] difficult | 16 |
|
| 5 | because it is difficult [verb] | 17 |
|
| 6 | because it is difficult [to-vb] | 17 |
|
